title: Sequence and domain conservation of the coelacanth Hsp40 and Hsp90 chaperones suggests conservation of function.
abstract: Molecular chaperones and their associated co-chaperones play an important role in preserving and regulating the active conformational state of cellular proteins. The chaperone complement of the Indonesian Coelacanth, Latimeria menadoensis, was elucidated using transcriptomic sequences. Heat shock protein 90 (Hsp90) and heat shock protein 40 (Hsp40) chaperones, and associated co-chaperones were focused on, and homologous human sequences were used to search the sequence databases. Coelacanth homologs of the cytosolic, mitochondrial and endoplasmic reticulum (ER) homologs of human Hsp90 were identified, as well as all of the major co-chaperones of the cytosolic isoform. Most of the human Hsp40s were found to have coelacanth homologs, and the data suggested that all of the chaperone machinery for protein folding at the ribosome, protein translocation to cellular compartments such as the ER and protein degradation were conserved. Some interesting similarities and differences were identified when interrogating human, mouse, and zebrafish homologs. For example, DnaJB13 is predicted to be a non-functional Hsp40 in humans, mouse, and zebrafish due to a corrupted histidine-proline-aspartic acid (HPD) motif, while the coelacanth homolog has an intact HPD. These and other comparisons enabled important functional and evolutionary questions to be posed for future experimental studies.
authors.affiliation: Department of Biochemistry, Microbiology and Biotechnology, Rhodes University Bioinformatics (RUBi), Rhodes University, Grahamstown, South Africa; Biological Sciences and Bioengineering, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey.
authors.forename: Özlem Tastan
authors.initials: ÖT
authors.lastname: Bishop
authors.forename: Adrienne Lesley
authors.initials: AL
authors.lastname: Edkins
authors.forename: Gregory Lloyd
authors.initials: GL
authors.lastname: Blatch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003600:Cytosol; D004721:Endoplasmic Reticulum; D005399:Fishes / Q000235:genetics*; D020869:Gene Expression Profiling; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics*; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics*; D018832:Molecular Chaperones / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011506:Proteins / Q000235:genetics*; D040681:Structural Homology, Protein
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D011506:Proteins